feat: allows labels + reverse dns at eip creation

[quentinalbertone]

Description

Allows labels + reverse dns at elastic ip creation

Checklist

(For exoscale contributors)

• Changelog updated (under Unreleased block, and add the Pull Request #number for each bit you add to the CHANGELOG.md)
• Testing

Testing

$ go run main.go compute elastic-ip create --label='a=1,b=2' --reverse-dns='example.net' --label='c=3'
 ✔ Creating Elastic IP... 3s
 ✔ Updating Elastic IP reverse dns... 0s
┼────────────────┼──────────────────────────────────────┼
│   ELASTIC IP   │                                      │
┼────────────────┼──────────────────────────────────────┼
│ ID             │ 025acc32-4d72-4240-b46a-461ef0b21c9c │
│ IP Address     │ 185.19.30.15                         │
│ Address Family │ inet4                                │
│ CIDR           │ 185.19.30.15/32                      │
│ Description    │                                      │
│ Zone           │ ch-gva-2                             │
│ Type           │ manual                               │
│ Reverse DNS    │ example.net.                         │
│ Instances      │                                      │
│ Labels         │ c:3                                  │
│                │ b:2                                  │
│                │ a:1                                  │
┼────────────────┼──────────────────────────────────────┼

$ go run main.go compute elastic-ip get 025acc32-4d72-4240-b46a-461ef0b21c9c
┼────────────────┼──────────────────────────────────────┼
│   ELASTIC IP   │                                      │
┼────────────────┼──────────────────────────────────────┼
│ ID             │ 025acc32-4d72-4240-b46a-461ef0b21c9c │
│ IP Address     │ 185.19.30.15                         │
│ Address Family │ inet4                                │
│ CIDR           │ 185.19.30.15/32                      │
│ Description    │                                      │
│ Zone           │ ch-gva-2                             │
│ Type           │ manual                               │
│ Reverse DNS    │ example.net.                         │
│ Instances      │                                      │
│ Labels         │ b:2                                  │
│                │ a:1                                  │
│                │ c:3                                  │
┼────────────────┼──────────────────────────────────────┼